Help needed with 83 gs450

[abelfonseca]

I bought an 83 gs450 about 2 months ago, the bike was running fine but from time to time the right cyclinder would die, randomly comming back to life some days later, this happened twice, after the last time it happened the bike seemed to run fine but I wansn't getting full acceleration and I noticed that my right cyclinder was no as hot as the left one, when I ran the bike only with the left cylinder it ran and iddled fine, when I tried to do this with the right cylinder only, the bike would stay on only if I squeezed the throtle a bit. also I noticed the the exaust coming from the right cylinder smelled like unburned gasoline. about two weeks later the bike started getting more difficult to start (before it would turn on right away not even needing to press on the choke), now it wont start at all, the starter just cranks and cranks but I get no ignition, I dont know if it is a single problem or a mix of problems, or if the fact that it does not start has to do with the issues I was having with the right cylinder before. This is my first bike and I would greatly appreciate your help.

Thanks for the Help.

[bgmart450]

Did you pull the spark plugs? Sounds like either you could be getting too much gas (rich) to the right cyl. I'd pull that plug and see what the bottom of it looks like.

Could also be a dead plug. If the plug looks good swap them and see if the problem switches sides.

Thats what I'd start with anyways...

[abelfonseca]

back when the bike was still running I pulled the plugs out, the right plug was a little black or carbon fouled the left plug was completely normal, I switched them but there was no change, the left cylinder still got hotter then the right, I then suspected it might be the right coil that was faulty but when I finally decided to switch the coils to see if the symptoms went to the other cyl the bike was not starting at all, I switched them anyways but it still wouldn't start, there is small hole on the bottom part of the right exaust pipe, about 1in^2 I dont know if that can be a factor that would cause the right cyl to no function properly or that could lead to the bike not starting at all.

[bgmart450]

Sounds like you might need a thorough carb cleaning....

I had massive leaks in my exhaust and it ran, even when I cracked the pipe completely just before the crossover she still ran.

I am betting on a carb issue. Either some part (needle sticking or float issue, etc) is malfunctioning or maybe something is gummed up.

Someone might have better ideas though...

Did you check spark by pulling the plugs and pluging the spark plugs back into the wires (one by one) and grounding them to the case and hitting the starter. Should be a pretty strong blue spark. Would at least exempt a spark/ignition issue.

[abelfonseca]

I just tried that a few minutes ago, there was no spark in the spark plugs, there was only a small spark between the hexagonal part of the plug and the engine block where it was grounded to, there was no actual spark in the spark plug gap, does this mean that my plugs are bad but the ignition system is ok or can it still be something else beside the plug?

[bgmart450]

You should get spark in the gap. You are grounding the gap only, right?

If that fails I would get new plugs and try again. I like to start cheap.

[ccratin]

You need to rebuild your petcock. More than likely it's leaking through the vacuum line which connects to the #2 right carburetor. Had the exact same problem with both of mine. Got the rebuild kits from cycle re-cycle.

Chris

[abelfonseca]

Finally, I could start the bike again!!! I went and got new spark plugs, that seemed to solve part of the problem, and yes there is fuel leakage into the vacuum line, I had noticed it before when the bike was running but I din't know it was something to be concerned with (I don't what the really is the purpose of the vacuum hose is, maybe to equalize pressure but not sure), so I went ahead and ordered the repair kit from cycle recycle, thanks a lot for your help Brent and Chris.

Abel Fonseca

[bgmart450]

Yeah, the gas should not flow when there is no vaccuum coming from the carbs. You should get that fixed soon. My wife's bike had the same issue and it allowed gas into the oil. Not the best combo for a lubricant...